Insulated container

ABSTRACT

The inner container and outer container which are formed from a transparent material are integrally formed leaving a space section therebetween, a thermally insulating layer is formed in the space section, and a radiation prevention film is formed on at least one of an outer surface of the inner container and an inner surface of the outer container. The radiation prevention film has a radiation prevention film omission section having a surface area which is 30% or less of the surface of the container on which the radiation prevention film is formed.

TECHNICAL FIELD

The present invention relates to a thermally insulated container havinga double-walled structure in which an inner container and an outercontainer are integrally joined leaving a space therebetween, and inparticular, the present invention relates to a thermally insulatedcontainer in which a radiation prevention film is formed on at least oneof the outer surface of the inner container or the inner surface of theouter container.

BACKGROUND ART

In recent years, thermally insulated metal containers having inner andouter containers made from metals such as stainless steel have beenwidely used in place of conventionally used glass vacuum flasks(hereinafter, referred to as “thermally insulated containers”). Becausethermally insulated metal containers are superior from the point of viewof strength, they are suitable for portable use.

Thermally insulated containers made from metal are made by arranging aninner container and an outer container, which are made of a metal suchas stainless steel, leaving a space section in between and joining theopening sections thereof to form an integrated double walled container,and the space section is used to form a thermally insulating layer. Inparticular, thermally insulated metal vacuum flasks in which the spacesection is evacuated to form a thermally insulating vacuum layer areused generally as thermally insulated containers whose temperaturemaintaining performance is excellent.

However, in the above-mentioned thermally insulated metal vacuumcontainer, since the inner and outer containers are metal, which is nottransparent, it is not possible to check the quantity of the contentsand the like from the outside, and in order to do this, it is necessaryto remove the lid or the stopper, and check the inside of the containerthrough the opening.

When checking the inside of the container, external air flows into theinside of the container. Therefore, when cold drink, for example, iscontained in the container, the temperature of the drink increases todue to the inflow of air. In addition, when a hot drink such as hotwater or the like is contained in the container, the temperature of thedrink falls.

For this reason, the temperature maintaining performance of theconventional thermally insulated container was degraded.

In addition, with the above-mentioned thermally insulated glasscontainers, in order to prevent thermal radiation and to increase thetemperature maintaining properties, it is common for a silver-platingfilm to be formed by means of a silver mirror reaction on the thermallyinsulating layer side of the inner or outer container. In this case, itis impossible to check the contents of the container from the outside.Therefore, in the same way as for the above-mentioned thermallyinsulated metal containers, there is a problem that maintenance of thetemperature of the contents of the container is insufficient.

In addition, in Japanese Unexamined Patent Application, FirstPublication No. 2000-60743, a thermally insulated container in which atransparent synthetic resin is used for the inner and outer containersis disclosed.

In this thermally insulated container, a thermally insulating layer isformed in which a gas having a thermal conductivity lower than air(hereinafter, referred to as low thermal conductivity gas), such askrypton, xenon, and argon, is enclosed within the space section.

In this thermally insulated container, to prevent thermal radiation, aradiation prevention film through which visible light can pass and whichabsorbs or reflects infrared radiation is provided on the surface of thethermally insulating layer side of the inner or outer container.

The radiation prevention film is formed by adhering a metal oxide, ametal nitride, or fine particles of metal on a film substrate in asingle layer or a multilayer by means of the vapor deposition,sputtering, ion plating, or the like.

With this thermally insulated container, since a radiation preventionfilm through which visible light can pass is used, it is possible tocheck the contents of the container from the outside through theradiation prevention film.

However, since the radiation prevention film used in this thermallyinsulated container has a high rigidity, it is difficult to form curvedsurfaces.

For this reason, it can be arranged on places such as flat sections, andsections which are broadly flat (such as the body of cylindricalsections), but arrangement on sections which are formed of curvedsurfaces such as the shoulders or bottoms of the container, or the like,is difficult.

In consideration of the above-mentioned circumstances, the presentinvention has an object of providing a thermally insulated containerwith which it is possible to visually inspect the contents, or the like,contained within the container, which has superior temperaturemaintaining performance, and which can be given an improved radiationprevention function by providing a radiation preventing performance onparts of the container which have curved surfaces as well as parts ofthe container which have flat surfaces.

DISCLOSURE OF INVENTION

The thermally insulated container according to a first aspect of thepresent invention comprises an inner container and an outer containerformed of a transparent material which are arranged leaving a spacesection therebetween, and which are integrally joined to form a doublewalled container, wherein the space section between the above-mentionedinner and outer containers of the double walled container forms athermally insulating layer, and a radiation prevention film is formed onat least one of the outer surface of the inner container and the innersurface of the outer container. The radiation prevention film has aradiation prevention film omission section having an area which is 30%or less of the container surface on which the radiation prevention filmis formed.

In the thermally insulated container, the transparent material may beglass.

In the thermally insulated container, the transparent material may besynthetic resin.

In the thermally insulated container, the thermally insulating layer maybe a vacuum insulation layer.

In the thermally insulated container, the thermally insulating layer mayenclose a low thermal conductivity gas.

In the thermally insulated container, the radiation prevention filmomission section may be formed in a slit shape in the axial direction ofthe container.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing an example of the thermallyinsulated container of the present invention.

FIG. 2 is an explanatory diagram for explaining the manufacturing methodof the thermally insulated container shown in FIG. 1.

FIG. 3 is a graph showing the relationship between the surface area ofthe radiation prevention film omission section and the temperaturemaintaining performance of the thermally insulated container.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the thermally insulated container of the presentinvention will be explained with reference to FIG. 1. FIG. 1 shows athermally insulated vacuum container made from glass as an example ofthe thermally insulated container of the present invention.

The thermally insulated container 1 shown here comprises a glass innercontainer 2 and a glass outer container 3. These inner and outercontainers 2 and 3 are formed having cylindrical shaped body sections 2c and 3 c, and neck sections 2 d and 3 d having diameters smaller thanthose of the body sections 2 c and 3 c formed in the upper sections ofthe body sections 2 c and 3 c.

The inner container 2 and the outer container 3 are arranged leaving aspace section 4 therebetween, and the rim sections 2 a and 3 a of eachopening are integrally joined, and thereby a double-walled container isformed. The space section 4 is vacuum evacuated to form a thermallyinsulating vacuum layer V.

A radiation prevention film 5 is formed on at least one of the surfaceson the space section 4 (thermally insulating vacuum layer V) side of theinner container 2 and the outer container 3, in other words, the outersurface 2 b of the inner container or the inner surface 3 b of the outercontainer. In the example shown in the figure, the radiation preventionfilm 5 is only formed on the outer surface 2 b of the inner container,and a radiation prevention film 5 is not formed on the inner surface 3 bof the outer container.

This radiation prevention film 5 may be formed only on the inner surface3 b of the outer container, or it may be formed on both of the outersurface 2 b of the inner container and the inner surface 3 b of theouter container. In addition, a tip tube 6 for vacuum evacuation or forgas substitution is provided at the bottom of the outer container 3.

As the radiation prevention film 5, metal films comprising gold, silver,copper, nickel, aluminum or the like can be used.

The radiation prevention film 5 is preferably formed by means of achemical plating method (such as silver mirror reaction), a vapordeposition method, a sputtering method, an ion plating method, a sol-gelmethod, a spray coating method, a dip coat method, or the like. Inaddition, a metal foil comprising aluminum or the like is also suitable.

When the thickness of the radiation prevention film 5 is 500 Å orgreater (50 nm or greater), a superior radiation prevention function canbe obtained, and in particular, when the thickness of the radiationprevention film 5 is 1000 Å or greater (100 nm or greater), an even moresuperior radiation prevention action can be obtained.

The radiation prevention film 5 has a radiation prevention film omissionsection 7 from which a portion of the radiation prevention film 5 hasbeen omitted.

The radiation prevention film omission section 7 is formed in a slitshape in the axial direction of the inner container 2, and thereby, itis possible to check from the outside the contents housed within theinner container 2.

The radiation prevention film omission section 7 is formed to have awidth that is approximately fixed from the rim section 2 a of theopening of the inner container 2 to the bottom of the inner container 2.

The radiation prevention film omission section 7 is formed so as to havesurface area which is 30% or less of the surface of the container onwhich the radiation prevention film 5 is formed. In the illustratedexample, the surface area of the radiation prevention film omissionsection 7 is set so as to be 30% or less than the surface area of theouter surface 2 b of the inner container.

When the area of the radiation prevention film omission section 7 is setso as to exceed 30% of the surface area of the outer surface 2 b of theinner container, the radiation prevention effect is degraded and thetemperature maintaining properties are degraded.

A lower limit for the surface area of the radiation prevention filmomission section need not be set, and as long as it is formed so that itis possible to check from the outside the contents housed within theinner container 2. The surface area of the radiation prevention filmomission section 7 can be suitably selected depending on the mode ofuse, but a surface area therefor of 5% or greater is preferable.

In forming the radiation prevention film 5, a method can be adopted inwhich a suitable masking material is arranged on the outer surface 2 bof the inner container at the place at which the radiation preventionfilm omission section 7 is to be formed. Thereafter, a chemical platingmethod (such as silver mirror reaction), vapor deposition method,sputtering method, ion plating method, sol-gel method, spray coatingmethod, or dip coat method is carried out on the outer surface 2 b ofthe inner container, and then the above-mentioned masking material isremoved.

In addition, the radiation prevention film 5 can be formed by means of amethod in which a metal foil in which an omitted section which forms theradiation prevention film omission section 7 is formed in advance isadhered to the outer surface 2 b of the inner container.

In the above-mentioned thermally insulated container 1, the spacesection 4 between the inner and outer containers 2 and 3 forms athermally insulating vacuum layer V which has. been vacuum evacuated.However, it is also possible to obtain superior insulation effects whenthe thermally insulating layer V is formed by enclosing a low thermalconductivity gas, such as krypton gas, xenon gas, argon gas, or thelike, in the space section 4.

In the above-mentioned thermally insulated container 1, glass was usedas the transparent material which forms the inner and outer containers 2and 3. However, in the present invention synthetic resin can also beused as the transparent material.

In that situation, it is preferable to make the thermally insulatinglayer V by enclosing a low thermal conductivity gas such as krypton gas,xenon gas, argon gas, or the like, in the space section 4.

In addition, as the radiation prevention film 5, metal film of gold,silver, copper, nickel, aluminum, or the like can be used. The radiationprevention film 5 is preferably formed by means of a chemical platingmethod (such as silver mirror reaction), a vapor deposition method, asputtering method, an ion plating method, a sol-gel method, a spraycoating method, or a dip coat method. In particular, a radiationprevention film obtained using a magnetron sputtering process method ispreferable.

In the following, a method for manufacturing the thermally insulatedglass vacuum container 1 shown in FIG. 1 will be explained withreference to FIG. 2.

Manufacture of the Inner and Outer Containers

Firstly, the inner container 2 is fabricated. In addition, an outercontainer 3 having a shape approximately the same as the inner container2 is fabricated. The outer container 3 is formed with dimensionssufficient to house the inner container 2 leaving a space section 4therebetween.

The outer container 3 is divided into an upper outer container 3A havingan opening rim section 3 a, and a lower outer container 3B having a tiptube 6 for gas evacuation of the bottom section.

Formation of the Radiation Prevention Film

The radiation prevention film 5 is formed by attaching a masking tape tothe outer surface 2 b of the inner container on the portion on which theradiation prevention film omission section 7 is to be formed, and thenusing a the chemical plating method (such as silver mirror reaction),vapor deposition method, sputtering method, ion plating method, sol-gelmethod, spray coating method, dip coat method, or the like.

Next, the masking tape is removed and the radiation prevention film 5 isformed with this portion being the radiation prevention film omissionsection 7.

Assembly of the Inner and Outer Containers

The upper part of the inner container 2 is housed,within the upper outercontainer 3A, and the opening rim section 2 a and the opening rimsection 3 a are air tightly bonded to each other.

At this time, a pad 8 is positioned between the inner container 2 andthe upper outer container 3A so as a space section 4 having a constantwidth is formed between these containers.

Next, the lower part of the inner container 2 is housed within the lowerouter container 3B. At this time, a space section 4 is formed betweenthe inner container 2 and the lower outer container 3B.

Next, the lower edge (joining section 3A′) of the upper outer container3A and the upper edge Joining section 3B′) of the lower outer container3B are bonded by welding, and thereby the upper outer container 3A andthe lower outer container 3B are unified to form a double-walledcontainer.

Vacuum Evacuation and Sealing

Finally, the space section 4 is vacuum evacuated via the tip tube 6 forevacuation until a prescribed vacuum (for example, 133.3×10⁻³ Pa orless) is reached. Then, the tip tube 6 for evacuation is welded andsealed, thereby forming the thermally insulating vacuum layer V in spacesection 4.

When a thermally insulated container is manufactured using inner andouter containers 2 and 3 which are made from a synthetic resin material,the joining of the upper outer container 3A and the lower outercontainer 3B may be carried out using an adhesive agent, an ultra-sonicwelder, or the like.

When a synthetic resin material is used, if the thermally insulatinglayer is formed by substitution with a gas having low thermalconductivity such as krypton gas, xenon gas, argon gas, or the like, andthen enclosing this gas having low thermal conductivity in the spacesection 4, it becomes possible for the thermally insulating propertiesto be maintained over a long period of time.

In the above-mentioned thermally insulated container 1, since theradiation prevention film 5 has a radiation prevention film omissionsection 7, it is possible to check the contents within the innercontainer 2 through the radiation prevention film omission section 7.

For this reason, when checking the contents, there is no need to openthe opening section by removing the lid or the like, and it is possibleto avoid changes to the temperature of the contents due to external air.

In addition, in the thermally insulated container 1, since the radiationprevention film 5 has a radiation prevention film omission section 7, itis possible to increase the thermal insulation performance compared witha thermally insulated container having a radiation prevention film 5 inwhich a radiation prevention film omission section is not formed.

Consequently, it is possible to improve the temperature maintainingproperties.

In addition, by means of forming a radiation prevention film 7, it ispossible to reduce the amount of metal used in the radiation preventionfilm 5, and thereby it is possible to reduce costs.

In addition, by means of forming the radiation prevention film omissionsection 7 in the shape of a slit in the axial direction of the innercontainer 2, it is possible to check the contents of the containerregardless of the position of the axial direction (for example, theposition of the height of the water surface) of the contents.

Consequently, irrespective of the quantity of the contents, it ispossible to check with certainty the contents and the amount of thecontents.

In addition, in the thermally insulated container 5, since it ispossible to form the radiation prevention film 5 by means of a chemicalplating method, a vapor deposition method, a sputtering method, an ionplating method, a sol-gel method, a spray coating method, a dip coatmethod, or the like, it is possible to form the radiation preventionfilm 5 on any shaped container surface, such as spherical surfaces,curved surfaces, angular surfaces, without limitation to flat surfaces.

For this reason, even when the outer surface of the inner container 2 bis a curved surface, it is possible to provide the radiation preventionfilm 5 and to obtain a superior temperature maintaining performance.

In addition, when the radiation prevention film 5 is formed by means ofa vapor deposition method or the like, by means of forming the film withthe bottom of the inner container 2 directed toward the vapor depositionsource, it is possible to make the radiation prevention film 5 thickerin the vicinity of the bottom of the inner container 2, and graduallythinner toward the opening section.

In this situation, it is possible to obtain a thermally insulatedcontainer 1 having a superior external appearance.

In addition, by means of carrying out the vapor deposition in acondition with the side surface of the inner container 2 toward thevapor deposition source, it is possible to form the radiation preventionfilm 5 so that it is thicker at a prescribed circumferential position ofthe side surface of the inner container, and gradually thinner in thecircumferential direction.

For example, by means of conducting the vapor deposition on theabove-mentioned side surface of the inner container at three differentplaces at circumferential positions separated by 120°, it is possible toform the radiation prevention film 5 so that it is thick at the threedifferent circumferential positions and thin at other places.

For this reason, it is possible to present a striped pattern, andthereby to obtain a thermally insulated container which is superior fromthe point of view of its external appearance.

In addition, it is possible use the thermally insulated container of thepresent invention with its strength increased by covering the outercontainer with a protective cover. This thermally insulated container issuitable for portable use.

In addition, the insulated container of the present invention can alsobe used as table-top container.

TEST EXAMPLE 1

Glass thermally insulated vacuum containers as shown in FIG. 1 wereprepared as follows.

Inner container 2 and outer container 3 were manufactured usingborosilicate glass and using a blowing machine.

A thermally insulated container 1 was manufactured using the innercontainer 2 and the outer container 3 following the above-describedmanufacturing method.

The specifications of the thermally insulated containers are shownbelow.

Inner Container 2

Wall thickness: approximately 1.5 mm; outer diameter of the opening rimsection 2 a: 38 mm; total height: 210 mm; external diameter of the body:90.0 mm; total surface area 580 cm².

Upper Outer Container 3A

Wall thickness: approximately 1.5 mm; inner diameter of the opening rimsection 3 a: 44.8 mm; total height: 80 mm; inner diameter of the body:99.8 mm.

Lower Outer Container 3B

Wall thickness: approximately 1.5.mm; inner diameter of the body: 99.8mm; total height: 139 mm.

Radiation Prevention Film 5

The radiation prevention film 5 was formed by means of attachingaluminum foil to the outer surface 2 b of the inner container.

As the aluminum foil, aluminum foil having an omission section(radiation prevention film omission section 7) in the form of a slitextending in the axial direction of the container was used. The ratios(the omission ratios) of the surface areas of the omission sections tothe surface areas of the outer surfaces 2 b of the inner containers wereas follows.

Omission Ratios: 5%, 10%, 20%, and 30%.

In addition, a thermally insulated container which did not have aradiation prevention film 5 was also made. This thermally insulatedcontainer corresponds to an omission ratio of 100%.

In addition, a thermally insulated container which did not have aradiation prevention film omission section 7 formed in the radiationprevention film 5 was made. This thermally insulated containercorresponds to an omission ratio of 0%.

The Thermally Insulating Layer V

After vacuum evacuation of the space section 4, krypton gas, which is alow thermal conductivity gas, was charged into the space section 4 to apressure roughly equal to atmospheric pressure or slight higher, and thetip tube 6 for evacuation was sealed.

1000 cc of hot water of approximately 100° C. was put into each of thesesix thermally insulated containers for which the surface area of theradiation prevention film omission section 7 was different, and then thethermally insulated containers were left in a constant temperature roomat 25° C. for three hours. FIG. 3 shows the change in temperature forthis case. In FIG. 3, the horizontal axis shows the passage of time(minutes), and the vertical axis shows the temperature (° C.) of thewater within the container.

COMPARATIVE EXAMPLE

Thermally insulated containers were manufactured with the space section4 filled with air without vacuum evacuation of the space section 4 orfilling with krypton gas.

The radiation prevention film 5 was formed by means of attachingaluminum foil in which an omission section (radiation prevention filmomission section 7) had not been formed (omission ratio of 0%) to theouter surface 2 b of the inner container.

In addition, a thermally insulated container was manufactured in which aradiation prevention film 5 was not formed. This thermally insulatedcontainer corresponded to an omission section ratio of 100%.

1000 cc of hot water of approximately 100° C. was put into each of thesetwo thermally insulated containers, and then the thermally insulatedcontainers were left in a constant temperature room at 25° C. for threehours. FIG. 3 shows the change in temperature for this case.

From FIG. 3, the following matters can be confirmed.

(1) The thermally insulated container comprising a radiation preventionfilm 5 having a radiation prevention film omission section 7 with anomission ratio of 5% has a superior temperature maintaining property upto three hours from the start of the test compared with a thermallyinsulated container having a radiation prevention film 5 formed over theentirety of the outer surface 2 b of the inner container (omission ratioof 0%).

(2) The thermally insulated container comprising a radiation preventionfilm 5 having a radiation prevention film omission section 7 with anomission ratio of 10% has a superior temperature maintaining property upto 2 hours and 30 minutes from the start of the test compared with thethermally insulated container having an omission ratio of 0%.

(3) It was confirmed that the thermally insulated container comprising aradiation prevention film 5 having a radiation prevention film omissionsection 7 with an omission ratio of 20% had a superior temperaturemaintaining property up to 1 hour from the start of the test comparedwith the thermally insulated container having an omission ratio of 0%.

(4) The thermally insulated container comprising a radiation preventionfilm 5 having a radiation prevention film omission section 7 with anomission ratio of 30% has a superior temperature maintaining property upto 30 minutes from the start of the test compared with the thermallyinsulated container having an omission ratio of 0%.

(5) The thermally insulated container of Test Example 1 in which thethermally insulating layer V was formed using a low thermal conductivitygas had a superior temperature maintaining property compared with thethermally insulated container of Test Example 2 in which the thermallyinsulating layer V was formed using air.

From these results (1) to (5), it is possible to make the followingobservations.

Compared with a case in which the radiation prevention film 5 is formedover the entirety of the outer surface 2 b of the inner container, for athermally insulated container 1 in which a radiation prevention filmomission section 7 is formed, it is possible increase the temperaturemaintaining property of the thermally insulated container 1.

In addition, even when the surface area of the radiation prevention filmomission section 7 is comparatively large, it is possible for superiortemperature maintaining properties to be exhibited in the short term.

For this reason, the surface area of the radiation prevention filmomission section 7 can be set in accordance with the requiredtemperature maintenance time.

TEST EXAMPLE 2

Thermally insulated glass vacuum containers as shown in FIG. 1 weremanufactured in the following way.

Inner and outer containers 2 and 3 as used in Test Example 1 werethoroughly washed. Thereafter, as a masking material, oil was applied tothe outer surface 2 b of the inner container, and to the inner surface 3b of the outer container in the axial direction of the container.

Next, the inner and outer containers 2 and 3 were joined to form adouble walled container. Then, the outer wall 2 b of the inner containerand the inner wall 3 b of the outer container were chemically platedusing a silver mirror reaction.

As a result, the masked sections (the sections to which oil was applied)formed the radiation prevention film omission sections 7, and radiationprevention films 5 were formed by forming silver plating films onsections other than the masked sections.

Next, after the space 4 was vacuum evacuated via the tip tube 6 forevacuation, the tip tube 6 for evacuation was sealed by welding, andthermally insulated containers 1 were obtained. The ratios (the omissionratios) of the surface areas of these radiation prevention film omissionsections 7 to the surface area of the outer surface 2 b of the innercontainer were 5%, 10%, 20%, and 30%.

In addition, a thermally insulated container in which a radiationprevention film 5 was not formed (omission ratio of 100%), and athermally insulated container in which a radiation prevention filmomission section 7 was not formed in the radiation prevention film 5(omission ratio of 0%) were manufactured. The

The same evaluation test for temperature maintaining performance as wascarried out in Test Example 1 was carried out on these six containers.

The results confirmed that the pattern of change in temperature overtime of the water within these six thermally insulated containers havingomission ratios from 0 to 100% is similar to the pattern of change intemperature over time of the water within the six thermally insulatedcontainers having omission ratios from 0 to 100% in Test Example 1,respectively.

INDUSTRIAL APPLICABILITY

In the thermally insulated container of the present invention, since theradiation prevention film has a radiation prevention film omittedsection, it is possible to check the contents within the inner containerthrough the radiation prevention film omission section. For this reason,when checking the contents, it is not necessary to open the opening byremoving the lid or the like, and it is possible to prevent changes inthe temperature of the contents due to external air.

In addition, when compared with a thermally insulated container having aradiation prevention film in which a radiation prevention film omissionsection is not formed, the thermally insulated container can increasethermal insulation performance. Consequently, it is possible to improvethe temperature maintaining properties.

By means of forming the radiation prevention film omission section in aslit shape in the axial direction of the container, irrespective of theposition of the axial direction of the container (for example, theposition of the height of the surface of the liquid), it is possible tocheck the contents. Consequently, irrespective of the quantity of thecontents, it is possible to check the contents and the amount thereofwith certainty.

In addition, in the thermally insulated container of the presentinvention, since it is possible to form the radiation prevention film bymeans of a chemical plating method, a vapor deposition method, or thelike, it is possible to form the radiation prevention film even when thesurfaces of the container are curved. Consequently, it is possible toincrease the radiation prevention function and to obtain superiortemperature maintaining properties.

What is claimed is:
 1. A thermally insulated container comprising aninner container and an outer container formed of a transparent materialarranged leaving a space section therebetween, and integrally joined toform a double walled container, wherein the space section between theinner container and the outer container of the double walled containerforms a thermally insulating layer, a radiation prevention film isformed on at least one of an outer surface of the inner container and aninner surface of the outer container, and the radiation prevention filmhas a radiation prevention film omission section having a surface areawhich is 30% or less of the surface of the container on which theradiation prevention film is formed.
 2. A thermally insulated containeraccording to claim 1, wherein the transparent material is glass.
 3. Athermally insulated container according to claim 1, wherein thetransparent material is synthetic resin.
 4. A thermally insulatedcontainer according to claim 1, wherein the thermally insulating layeris a vacuum insulation layer.
 5. A thermally insulated containeraccording to claim 1, wherein the thermally insulating layer encloses alow thermal conductivity gas.
 6. A thermally insulated containeraccording to claim 1, wherein the radiation prevention film omissionsection is formed in a slit shape in the axial direction of thecontainer.